composedPath fallback via unfolding

fp-ts.composedPath.ts

import { array } from 'fp-ts/lib/Array';
import { flow, tuple } from 'fp-ts/lib/function';
import * as Option from 'fp-ts/lib/Option';

export const composedPath = (e: MouseEvent) => {
  if (e['composedPath']) {
    return e.composedPath();
  }

  if (e.target instanceof HTMLElement) {
    return array.unfold(
      e.target,
      flow(
        Option.fromNullable,
        Option.map(element => tuple(element, element.parentElement)),
      ),
    );
  }

  throw new Error(`Cannot find DOM element path for event: ${event}. Is the target a HTML Element?`);
};